Up to now, products have, in practice, been positioned on or fed into packaging carriers at an infeed station so as to convey them, together with the packaging carriers, from the infeed station along a packaging line to downstream work stations, such as a sealing station. In the sealing station, a cover film is sealed onto the packaging carriers for hermetically sealing the products in the packaging carriers.
Conveying (transporting) the products on the packaging carriers between the infeed station and the sealing station does not cause any problems as long as the products do not shift on the packaging carriers. Such shifting may have the effect that they move into the packaging carrier area where the cover film is to be sealed on subsequently. This is normally a boundary area or the area of the sealed seam of the packaging carrier.
In particular the conveyance of long, flexible and partially curved products proved to be problematic, since such products tend to shift on the packaging carriers while they are being conveyed or since, for example, one end of the product projects beyond the packaging carrier simply in view of a curvature of the respective product. This has the effect that the products project beyond the packaging carriers and get into the area where sealing is intended to be carried out subsequently.
In order to detect shifting of the products, camera systems are used in practice. When the camera system detects that the products are no longer appropriately positioned on or in the packaging carriers, (i.e., project into the area to be sealed), the packaging process is stopped automatically. Subsequently, the operator must correct the position of the products on or in the packaging carriers so that the packaging process can continue. This is disadvantageous primarily insofar as the camera system used for this purpose is expensive and the automatic stopping of the packaging process leads to downtimes, whereby manufacturing costs are increased.
It has also turned out in practice that shifting of the products on the packaging carriers is caused primarily by vibrations of the packaging machine, by cyclic feeding along the conveyor path, by closing the sealing tool of the sealing station and also by restoring forces of the products as such. Primarily, however, the cyclic advance of the products on the packaging carriers along the packaging line is considered responsible for the circumstance that the products, while being conveyed, move away from their original position and possibly into the packaging carrier area to be sealed.